A typical image forming apparatus such as a printer or a multifunction peripheral (MFP) transfers to a state (“standby mode”) for energy saving, as energy-saving measures, if a preliminarily set time has elapsed in a state in which a user does not use the image forming apparatus. However, once the image forming apparatus transfers to the standby mode, it takes time to be put back into a state (“normal mode”) in which the user can use the image forming apparatus.
If, for example, a client apparatus transmits, to the image forming apparatus in the standby mode via a network, information request data for confirming information of the image forming apparatus, the image forming apparatus transfers from the standby mode to the normal mode and transmits response data, which takes time. Therefore, transmitting information request data from the client apparatus multiple times throughout a day results in a corresponding increase in transitions from the standby mode to the normal mode, which reduces the amount of time of being in the standby mode, thereby reducing an energy-saving effect.
To combat this, one image process apparatus enables response data to be transmitted even in the standby mode. Such an image process apparatus includes a controller having two Central Processing Units (CPUs), with a main CPU responding in a normal mode and a sub CPU responding in a sleep mode.
In the normal mode, the main CPU stores response data in a random access memory (RAM) in the main CPU. At the time of transferring to the sleep mode, the sub CPU acquires a piece of response data, whose frequency of use is high, from the RAM in the main CPU and stores the piece of response data in a RAM in the sub CPU.
As described above, at the time of transferring from the normal mode to the sleep mode, the piece of response data whose frequency of use is high is stored in the RAM in the sub CPU. Therefore, the above-described image process apparatus can generate and transmit a piece of response data using data stored in the RAM in the sub CPU by the sub CPU in the sleep mode.
However, it is necessary for the above-described image process apparatus to preliminarily store pieces of response data in the RAM in the main CPU in the normal mode, and it is necessary for the sub CPU to acquire a piece of response data whose frequency of use is high from among the pieces of response data stored in the RAM in the main CPU when the image process apparatus transfers to the sleep mode and to transfer the acquired response data to the RAM in the sub CPU. As a result, there is an accompanying delay before the transition to the sleep mode.